Summary:
This is the follow-up patch for http://reviews.llvm.org/D19436
* Update the discriminator reading algorithm to match the assignment algorithm.
* Add test to cover the new algorithm.
Reviewers: dnovillo, echristo, dblaikie
Subscribers: danielcdh, dblaikie, echristo, llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D19522
llvm-svn: 267945
Dehao Chen